Optimal equilibria of the best shot game

We consider any network environment in which the "best shot game" is played. This is the case where the possible actions are only two for every node (0 and 1), and the best response for a node is 1 if and only if all her neighbors play 0. A natural application of the model is one in which the action 1 is the purchase of a good, which is locally a public good, in the sense that it will be available also to neighbors. This game typically exhibits a great multiplicity of equilibria. Imagine a social planner whose scope is to find an optimal equilibrium, i.e. one in which the number of nodes playing 1 is minimal. To find such an equilibrium is a very hard task for any non-trivial network architecture. We propose an implementable mechanism that, in the limit of infinite time, reaches an optimal equilibrium, even if this equilibrium and even the network structure is unknown to the social planner.Comment: submitted to JPE

World on Fire? Democracy, Globalization and Ethnic Violence

Recent studies suggest that democracy and globalization lead to ethnic hatred and violence in countries with a rich ethnic minority. We examine the thesis by Chua (2003) that democratization and globalization lead to ethnic violence in the presence of a market-dominant minority. We use different data sets to measure market dominant minorities and employ panel fixed effects regressions for a sample of 107 countries over the period 1984-2003. Our model contains two-way and three-way interactions to examine under which conditions democracy and globalization increase violence. We find no evidence for a worldwide Chua effect, but we do find support for Chua’s thesis for Sub-Saharan Africa.Globalization, Democracy, Ethnic Violence, Market-dominant minorities

Spatially separated polar samples of the cis and trans conformers of 3-fluorophenol

We demonstrate the spatial separation of the cis- and trans-conformers of 3-fluorophenol in the gas phase based on their distinct electric dipole moments. For both conformers we create very polar samples of their lowest-energy rotational quantum states. A >95 % pure beam of trans-3-fluorophenol and a >90 % pure beam of the lowest-energy rotational states of the less polar cis-3-fluorophenol were obtained for helium and neon supersonic expansions, respectively. This is the first demonstration of the spatial separation of the lowest-energy rotational states of the least polar conformer, which is necessary for strong alignment and orientation of all individual conformers.Comment: 5 pages, 5 figure

Trade and Business Cycle Synchronization in OECD Countries - a Re-examination

This paper re-examines the relationship between trade intensity and business cycle synchronization for 21 OECD countries during 1970-2003. Instead of using instrumental variables, we estimate a multivariate model including variables capturing specialisation, financial integration, and similarity of economic policies. We confirm that trade intensity affects business cycle synchronization, but the effect is much smaller than previously reported. Other factors in our model have a similar impact on business cycle synchronization as trade intensity. Finally, we find that the effect of trade on business cycle synchronisation is not driven by outliers and does not suffer from parameter heterogeneity.business cycles, trade, synchronization of business cycles

Paying Positive to Go Negative: Advertisers' Competition and Media Reports

This paper analyzes a two-sided market for news where advertisers may pay a media outlet to conceal negative information about the quality of their own product (paying positive to avoid negative) and/or to disclose negative information about the quality of their competitors' products (paying positive to go negative). We show that whether advertisers have negative consequences on the accuracy of news reports or not ultimately depends on the extent of correlation among advertisers' products. Specifically, the lower the correlation among the qualities of the advertisers' products, the (weakly) higher the accuracy of the media outlet' reports. Moreover, when advertisers' products are correlated, a higher degree of competition in the market of the advertisers' products may decrease the accuracy of the media outlet's reports.

Submillimeter-Wave Measurements and Analysis of the Ground and ν2 = 1 States of Water

In order to facilitate further studies of water in the interstellar medium, the envelopes of late-type stars, jets, and shocked regions, the frequencies of 17 newly measured H_2 ^(16)O transitions between 0.841 and 1.575 THz are reported. A complete update of the available water line frequencies and a detailed calculation of unmeasured rotational transitions and transition intensities as a function of temperature are presented for the ground and ν_2 = 1 state levels below 3000 cm^(-1) of excitation energy. The new terahertz transitions were measured with a recently developed laser difference frequency spectrometer. Six of these transitions arise from the ν_2 = 1 state, and the other 11 are in the ground state; all have lower state energies from 700 to 1750 cm^(-1) and should be accessible to Stratospheric Observatory For Infrared Astronomy (SOFIA) through the atmosphere. The transitions near 0.850 THz are accessible from the ground with existing receivers. Observations of the newly measured ν_2 = 1 state transitions, which include the 1_(1, 1)-0_(0, 0) fundamental at 1.2057 THz and five other very low J transitions, should provide valuable insights into role played by the ν2 = 1 state in the cooling dynamics of jets, shocks, masers, and strongly infrared-pumped regions. The line list is presented to assist in the planning of observational campaigns with the Far-Infrared Space Telescope (FIRST) and other proposed space missions with which a full suite of water observations can be carried out

A High Power Frequency-Stabilized Tunable Two-Frequency Diode Laser System for the Generation of Coherent THz-Waves by Photomixing

A tunable two-frequency high-power diode laser system at 850 nm for terahertz (Thz)-wave generation by photomixing in low-temperature-grown GaAs photo-conductors has been developed. The difference frequency is obtained through a three laser system, where two lasers are locked to different orders of a Fabry-Perot cavity and a third is offset-locked to the first, The difference-frequency signal is generated by the offset laser and the other cavity-locked laser. The spectral purity of the beat note is better than 1 MHz. The maximum output power of -500 mW was obtained by using the master oscillator power amplifier (MOPA) technique, simultaneous injection of two seed frequencies with a single semiconductor optical amplifier. Here we report the generation of THz waves and spectroscopy of acetonitrile as proof of concept

Аналіз зовнішньої заборгованості країн «Великої сімки»: виклики та перспективи (The analysis of external indebtedness of the G7 countries: challegences and perspectives)

Проблема зовнішньої заборгованості розвинутих країн привертає все більше уваги дослідників, оскільки за останні десятиліття спостерігається помітне зростання обсягу зовнішнього державного боргу розвинутих кра- їн, темп прирісту зовнішньої заборгованості перевищує темп економічного зростання, про що свідчить зростання показника зовнішній борг-ВВП. У контексті аналізу зовншіньої заборгованості країн «Великої сімки», встановлено, що послаблення продуктивності сприяє посиленню боргового тягаря на економіку даних країн. Незважаючи на пожвавлення економічного зростання, майже серед усіх країн G7, недостатня продуктивність не сприятиме послабленню зовнішньоборгового тягаря. (The problem of the external indebtedness of developed countries draws more attention and concern nowadays, since there has been a considerable increase in the level of the external debt of developed countries for the last decades. Moreover, the increment rate of external indebtedness outpaces the increment rate of economic growth and an increase in the external debt-to-GDP ratio of developed countries underpins the tendency. The debt dynamics of G7 countries draw special attention, since those countries represent the majority of net global wealth, generate half of the global GDP and are the top-ranking economies according to the Human Development Index. Despite the fact that almost all the G7 economies have managed to boost economic growth, an inadequate rate of productivity is hardly likely to alleviate debt pressure. It is recommended to address the productivity issues, since the tendency of external indebtedness accumulation to outpace economic growth increases the cost of necessary reforms and adjustments.

A designed phenylalanyl-tRNA synthetase variant allows efficient in vivo incorporation of aryl ketone functionality into proteins

Incorporation of non-natural amino acids into proteins in vivo expands the scope of protein synthesis and design. p-Acetylphenylalanine was incorporated into recombinant dihydrofolate reductase (DHFR) in Escherichia coli via a computationally designed mutant form of the phenylalanyl-tRNA synthetase of the host. DHFR outfitted with ketone functionality can be chemoselectively ligated with hydrazide reagents under mild conditions